Chin-up (Underhand Grip)
The Chin-up (Underhand Grip) is a compound bodyweight exercise that builds upper body strength by targeting the latissimus dorsi and biceps. By using a supinated grip, this movement places significant emphasis on arm development while effectively training the back.
Iridium attributes volume from this vertical pull to both your lat and bicep landmarks to ensure neither muscle group exceeds its Maximum Recoverable Volume. Because the underhand grip places significant demand on the arms, the AI checks your recent bicep fatigue status before programming this movement to guarantee your grip strength doesn't fail before your back does.
Form Cues
- Grip the bar shoulder-width apart with palms facing toward you
- Start from a full dead hang with arms completely extended
- Drive your elbows down and back to pull your upper chest to the bar
- Squeeze your biceps and lats firmly at the top of the movement
- Lower yourself under control until your arms are fully straight again
- Don't use momentum or kick your legs to generate upward force
- Don't let your shoulders roll forward or shrug toward your ears
- Don't shorten the range of motion by stopping before arms are straight
- Don't stretch your neck forward just to clear the bar with your chin
Common Mistakes
- Incomplete range of motion
- Excessive swinging or kipping
- Rounding the shoulders forward
- Dropping too quickly on the descent
- Hyper-extending the lower back
Muscles Worked
This exercise primarily targets the latissimus dorsi (lats) to build back width and strength. The underhand (supinated) grip places the biceps in a mechanically advantageous position, making them a primary mover alongside the back muscles, while the forearms and core work constantly to maintain grip and stability.
Primary
Secondary
Get Personalized Coaching for Chin-up (Underhand Grip)
Don't guess your way through weights or workouts. Download Iridium for automatic, AI-powered coaching that adapts to your recovery and goals.